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Gantry hoist or crane for engine installation?

settimo velo

Contributing Member
I am thinking about the best way to get my 2 V6s into the boat. The aft deck is about 6 foot off the ground and the boat is on stands, so I am either going to need a crane with operator or to build a gantry over the boat. I will probably need to take them in and out a few times, as I can see that some modifications to the engine bearers / bay could be required if I have overloooked anything. The gantry seems like the best way to go under the circumstances ... hoist the engine at the side of the boat, move it along the gantry, lower into position, switch lifting eye for alignment adjustment ...

However, that's just the theory! What way would you do it? Any advice would be much appreciated.
 
OK I know this may be a bit much but many years ago when we use to do weekend engine swaps in cars and trucks for friends we used a old truck, we removed the bumbers and attached 2 inch pipe to it and a come along or chain fall to lift and transport the engines around the yard/driveway.

Attached is a very rough drawing but I hope you get the idea of the set up. Real cheap, just buy or borrow the pipe and chain fall and a bunch of bolts and nuts....


View attachment 1966
 
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I assume this will be your first time humping lumps so here's my 2 cents worth. My general overarching guidelines....
Don't try and move the boat. If it's on a trailer ( I know, yours is blocked ) you cannot get it to go where you want it. Always move the lifting device.
You need something that allows fine adjustment of position without a great deal of effort; that is, the thing holding the engine has to be easy to move a quarter inch in any direction or you will be hating life.
Hydraulics trump mechanical every time.
Helpers are no help. Hate to say it but helpers take more time and attention than the actual doing of the task itself. If you can rig it so that you can do it yourself you will be way ahead of the game.
Apply the rule of threes. It will take three times longer and cost three times as much as your estimate.
 
I'm thinking that an i beam gantry will be the way to go, but as I have not used on of these before I am wondering how easily the beam trolley will shift along the beam when the load is hoisted? I want something that (as o2batsea suggests) will move with some degree of precision. Also, most of the safety stuff I have read says that the gantry should not be moved on its castors when underload. However, I can that this (fore and aft) movement may be of use (and safer) when the engines have been lowered down into the engine bay ...?
 
I made this and used it to lift my 5.7L up and move it forward to replace the flywheel and engine coupling.

For your purposes, it would have to be longer to extend past your transom (say 12' long), and higher so the engne(s) would clear your transom (16'?). As such, I would add additional posts midway between the corner posts and add additonal diagonal bracing at the top. And since you have two engines to hoist, put 2 beams (double up 2x10s) in line with where the engines would go.
Key to doing this safely is to make sure there's no way for the load to sway outside the perimeter of the posts, otherwise she'll tople.

View attachment Engine Gantry.pdf

Another tought is to put the boat on a trailer, use a ganrty to lift an engine, then back the boat underneath it.
 
I used a 2 x 10 lashed between 2 trees wider then my boat on a trailer.

I just backec my boat under it, and then with a hoist yanked the motor out. Then pulled the boat back out from under the motor. and then lowered the motor to my trailer that i had hookked up to my riding lawnmower. I actually stripped off the parts of the old motor i needed to install on my new motor and left the old motor on the trailer to being to the junkie.

Then i backed the boat i was yanking the new motor out of under the hoist and did it all over again .

I had the new motor on a pallet right under the hoist on the ground and installed the parts on it and up it went half way and i painted the motor 4- 5 times it was hot in about 2 hours it was dry.

Then hoisted it up backed under the boat and in it went. Was actually easy once everything was set up. The 2 x 10 is still in the trees in my backyard.
 
Chief, his boat is on stands. I don't think he'll be moving it.
Your way works fine if there's one engine and you just pull the boat forward and then roll it back exactly when you reinstall the engine. With enough chain the engine will swing around so as to let you nudge it where you want.
 
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I made this and used it to lift my 5.7L up and move it forward to replace the flywheel and engine coupling.

For your purposes, it would have to be longer to extend past your transom (say 12' long), and higher so the engne(s) would clear your transom (16'?). As such, I would add additional posts midway between the corner posts and add additonal diagonal bracing at the top. And since you have two engines to hoist, put 2 beams (double up 2x10s) in line with where the engines would go.
Key to doing this safely is to make sure there's no way for the load to sway outside the perimeter of the posts, otherwise she'll tople.

View attachment 1967

Another tought is to put the boat on a trailer, use a ganrty to lift an engine, then back the boat underneath it.

Interesting ... I've been thinking about building something in wood, as I have more skill with wood than metal and I only have 750 lbs to shift. As I need to be able to hoist the load at the side of the boat and then traverse it I've been wondering how to do this. My best idea so far is to have 2 parallel wood beams (approx. 12" X 4" reinforced ply box sections) with a trolley car (riding on 4 industrial wheels) in a track along the top of the beams. The hoist could be suspended in the gap between the beams and a horizontal pulley system could be set up to traverse the car when it is under load .... I think it could work.
 
I've used a few real no-**** gantrys before, with the little trolley on rollers on the beam... under load, it be be a real PIA to traverse the trolley, and once you start pushing on the load, the tendancy is for the load to start swaying. If you build it out of wood, a swaying 750# load, add some torsional stresses to the wooden frame and it can turn into a real hazard to anyone's health that is anywhere close as the whole mess comes tumbling down.

Put a chain hoist on each end of the beam running over the path you want to move the engine(s). Build it tall enough to allow room for the hoists to do their thing, and you can move the load between the two points with exact control.

BTW, if your happen to be planning on building a deck, like I did after I was done with mime, the lumber won't go to waste when your're done hoisting engines around.
 
If you are going to make a gantry out of wood I would suggest one that looks like this. See attached.

Also if you mount caster wheels to the bottom it will easily move anywhere you want.



View attachment 1969
 
I've used a few real no-**** gantrys before, with the little trolley on rollers on the beam... under load, it be be a real PIA to traverse the trolley, and once you start pushing on the load, the tendancy is for the load to start swaying. If you build it out of wood, a swaying 750# load, add some torsional stresses to the wooden frame and it can turn into a real hazard to anyone's health that is anywhere close as the whole mess comes tumbling down.

Put a chain hoist on each end of the beam running over the path you want to move the engine(s). Build it tall enough to allow room for the hoists to do their thing, and you can move the load between the two points with exact control.

BTW, if your happen to be planning on building a deck, like I did after I was done with mime, the lumber won't go to waste when your're done hoisting engines around.

Yes, I don't like the idea of shoving the load and getting the whole thing off balance! ... I can see that problem arising with a basic trolley, but I think it is possible to get hold of a trolley with a built in wheel that you can turn to move the trolley along the i beam. Alternatively I would've thought that it would be possible to attach some form of pulley block tackle to the trolley - horizontally between the trolley and the A frame - and to use this to exert enough force on the trolley to move it? I not sure that I really understand how a second hoist would be used to traverse the load along the beam, unless it is used to swing the load up so that the other trolley can then be shifted along the beam thus lowering the load approximately into position ... is that what you mean? kghost's A frame type structure is what I had in mind but with twin parallel top beams and a trolley riding on top of these.
 
Lift.jpg

1- lift load straight up by lifting with hoist A, taking in the slack of hoist B.

2- traverse the load by simultaneously taking up the load with hoist B and letting out chain from hoist A. A little practice and co-ordination between the two hoist operators and you can do this with very little to no vertical motion.

3- lower the load by lowering with hoist B, using hoist A to fine tune the positioning as it lowers into place.
 
Since the boat is out of the water, hire a tow truck to lift it in for you. If you have everything ready and he doesn't need to wait for you to do a lot of stuff, it'll be cheap AND safe. Did this all the time when I was driving a wrecker along the Massachussettes coast. Even did it along side the pier with the boat in the water, some times.. A wrecker with a hydraulic boom works perfect. Beats tipping over your gantry and dropping the motor on the boat, or worse.
 
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View attachment 1977

1- lift load straight up by lifting with hoist A, taking in the slack of hoist B.

2- traverse the load by simultaneously taking up the load with hoist B and letting out chain from hoist A. A little practice and co-ordination between the two hoist operators and you can do this with very little to no vertical motion.

3- lower the load by lowering with hoist B, using hoist A to fine tune the positioning as it lowers into place.

Got it! Thanks. Brilliant diagram. Probably explains why I keep seeing gantries for sale with two hoists on them.
 
Below is a link to the one I use to do repowers on site. It takes two people to stand it up after it is assembled but It works great. It takes about 30 minutes to assemble. I can move it around while it has a load on it. I cut the top I-beam and added a new one to make it 13 feet wide. It's adjustable to 14' in height.


http://www.harborfreight.com/media/...eab33525d08d6e5fb8d27136e95/i/m/image_859.jpg

... and what kind of trolley do you have on it? Does it traverse along the beam with ease when under load?
 
... and what kind of trolley do you have on it? Does it traverse along the beam with ease when under load?

It moves very easily along the I beam, sometimes too easily. I have installed 30 plus engines with this gantry. Works perfect. And it's safe.

If you look at the picture on the link, you can see the trolly. I have the exact one.
 
It moves very easily along the I beam, sometimes too easily. I have installed 30 plus engines with this gantry. Works perfect. And it's safe.

If you look at the picture on the link, you can see the trolly. I have the exact one.

Just looked at the Harbour Freight web site. That's amazing for $699! Here in Rip Off Britian it'd be a used one at that price. Just the cost of the wood I'd need to make a gantry would be around $300. The 20% tax the Her Majesty's Government take on every sale and the eye watering cost of a litre of petrol ($2 now!) is escalating prices ... Necessity is the Mother of Invention!
 
Now that plain f--ked up. Or like you say over there buggers.

Me i would chop down some free trees and lash together one. Or does all the trees belong to the queen also.

Where is the boat near the shore in your backyard where.

See my thinking is this if it's at a marina then for a few quid you should get someone to lift them for you.
 
In the end I built this:

Gantry.jpg

I took kghost's idea of A frames, which I doubled up and built out of 2" x 4". I then built twin I beams out of 1" and 3/4" ply. I mounted these on top of the A frames, in parallel. I then built a trolley car to run in a track, on top of the I beams, on 4" industrial wheels. A 2 ton hoist is suspended from a strop which hangs from the trolley car between the I beams:

Hoist.jpg

... and it works! I have already test lifted one engine into position with it. I plan to keep it for future projects.
 
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